In the field of pedagogical aids for teaching individuals in structured or personalized situations many types of teaching devices ranging from simple flash cards to costly and sophisticated audio-visual aids have been employed. However, such devices generally require the presence of a supervisor or operator. Devices designed for self-instruction often are either too complicated for young students or else too boring in continued use to be of significant long-term instructional benefit. Furthermore, simple hand operated devices often are designed solely for right-hand operation and also for presenting merely a single sequence of problems and solutions thereby inadvertently encouraging the student to memorize the sequence presented rather than to concentrate on and learn the solutions to the problems presented by the teaching device.